Paper making machine



Oct. 14, 1958 M. ALLEMANN PAPER MAKING MACHINE Filed June 22, 1955 2Sheets-$heet 1 INVENTOR.

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/f. 14 ATTO/F/VEK Oct. 14, 1958 M. ALLEMANN PAPER MAKING MACHINE FiledJune 22, 1955 2 Sheets-Sheet 2 INVENTOR. MART/N ALLEMA/wv. BY {4 W,

ATTORNEK United States Patent PAPER MAKING MACHINE Martin Allemann,Winterthur, Switzerland, assignor to Sulzer Frres, Socit Anonyme,Winterthur, Switzerland, a corporafion of Switzerland Application June22, 1955, Serial No. 517,185 Claims priority, application SwitzerlandJune 23, 1954 11 Claims. (Cl. 92-47) The present invention relates to amachine for making lengths of paper or cellulose including means fordrawing liquid from the pulp or paper mat, and including at least oneblower or compressor. The pulp or paper mat is supported by an endlesswire screen belt in the wet end of the machine, the belt forming a loopand having an upper run whose end is adjacent to the dry end of themachine for transferring the paper mat to the dry portion of themachine. A suction roller is provided at the aforementioned end of thescreen belt and outside of the loop formed by the belt. The suctionroller is normallyadjacent to the screen belt, but can be lifted awayfrom the belt for selectively allowing the paper mat to remain on thebelt, until the belt moves from the upper run to the lower run,whereupon the paper mat or pulp drops from the belt into a container, orfor lifting the paper mat from the belt for transferring it to the dryportion ofthe machine.

The object of the invention resides in the provision of means forautomatically lifting the aforesaid suction roller from the beltwhenever an undesired operating condition occurs in the machine. Such anundesired operating condition may be an increase of the pressure in anyone of the suction devices through which water is drawn out of the wetpulp or paper mat, rendering the suction device inoperative andnecessitating stoppage of the machine and transfer of the pulp or papermat from the endless screen belt in the wet portion of the machine intoa container from which the mass can be returned to a reservoir fromwhich it is again placed on the screen belt. Such a condition prevailsparticularly if the pressure in a suction roll which is adjacent to thescreen belt and inside of the loop formed thereby increases so that thepulp or paper mat is insufficiently or not at all dried and is still wetwhen it approaches the ing to the invention prevents damage to thescreen belt caused by such accumulationsor, congestion of the wet mass,for example tearing of the screen belt or undesired stretching andpermanent deformation of the screen belt resulting in unduly largemeshes. I

In an embodiment of the invention, a device is provided for lifting thesuction roller which is normally on top of the upper run of the loopformed by the screen belt (henceforth called the outside roller), whichdevice is actuated upon an undesired pressure in a suction roll adjacentto the screen belt and inside of the loop formed by the screen belt(henceforth called the inside roll). The outside suction roller islifted upon a predetermined increase of the suction pressure in theinside suction roll which increase may be caused by failure of theblower or its drive, or leakage in the conduit-connecting the blowerwith the inside suction roll.

2,855,829 Patented Oct. 14, 1958 ice The outside roller may be connectedwith a piston reciprocatively movable in a cylinder which is suppliedwith a pressure fluid whose flow is controlled by a valve actuated independence on the pressure in the inside suction roll. A bellows ispreferably arranged whose interior communicates with the interior of thesuction con'duit connected with the inside suction roll. The aforesaidvalve is operated by means of a solenoid which is interposed in anelectric circuit which is controlled by a mercury tumbler switch, thelatter being actuated by the aforesaid bellows.

In another modification of the invention, the blower is driven by anelectric motor and the outside suction roller is lifted away from thescreen belt if'themotor driving the blower becomes inoperative, forexample because of lack of electric current. In this case, the liftingmechanism becomes operative immediately upon failure of current supplyto the motor, i. e. before the (slowly rising) pressure in the suctionconduit connected with the blower reaches a point when the liftingmechanism would be actuated by a device responsive to the suctionpressure in the inside suction roll.

In a third, modification of the invention, the current supply to theelectric motor driving the blower is interrupted when the water level ina water separator interposed in the suction conduit connecting theblower with the insidev suction roll reaches a predetermined elevationand the lifting mechanism for the outside roller is actuated when thecurrent supply to the motor is interrupted In this case, theliftingmechanism is actuated at the moment at which the motor is stopped, incontradistinction to arrangements inwhich the lifting mechanism isactuated by the rising suction pressure, i. e. much later than when themotor is stopped.

The lifting mechanism is preferably so arranged that the mechanism forinterrupting the current supply to the motor simultaneously actuates thelifting mechanism.

In an embodiment of the invention, the water separator forms an electriccondenser vwhose capacity is used for simultaneouslyactuating thelifting mechanism and cutting out the current supply to the electricmotor driving the blower. The arrangement is particularly reliablebecause rests of pulp or paper, which may be in the water in theseparator and which impede the reliable operation of mechanical meansresponding to the water level in the water separator, have no influenceon the functioning of the water separator as an electric condenser. Inthis case, the metallic casing of the condenser forms one electrode ofthe condenser and an insulated rod extending into the casing above themaximum water level therein forms the other electrode. The water in thecondenser forms the dielectric and the capacity of the condenser dependson the water level in the water separator. The condenser forms part ofan alternating current circuit in which the intensity of the currentcorresponds to the water level inthe water separator. The current may beamplified by means of'a conventional amplifying arrangement. A relais isinterposed in the aforedescribed circuit. Therelais is actuated at apredetermined intensity of the current in the circuit and simultaneouslyactuates, bysuitable conventional means, a device for interrupting thecurrent supply to the motor driving the blower and a device foractuating the lifting mechanism for the outside roller. Since therelative dielectric constant of water is very great, approximately 81,the last described system for the combined actuation of the liftingmechanism and the device for stopping the motor is sufficientlysensitive.

The novel features which are considered characteristic of the inventionare set forth' with particularity in the appended claims. The inventionitself however and addi- 3 tional objects and advantages thereof willbest be understood from the "following description "of embodimentsthereof when read in conjunction with the accompanying drawing, inwhich- 'Fig. l is a schematic illustration of a part "of ap'apermakingmachine according to'the invention; 7

Fig. 2 is "a diagrammatic sectional view of 'a device used in themachine shown in Fig. 1;

Fig. 3 is a diagrammatic sectional illustration'of another deviceusablein connectionwith the plant'shown in Fig.1; p

Fig. '4is a diagrammatic illustration of 'a third device which maybeused in connectionfwith the plant shown in "Fig. 1.

The same numerals designatethesameparts' in all figures.

Referring more particul'arly'to Fig. 1 of the drawing, numeral 23'design'ates an endless screen band or belt which is usually woven ofcopper wire, and which supports the pulp or mat of'paper 24. Only theportion of the screen belt is shownwhich is adjacent to the dry part ofthe machine which is at the right of the belt 23. The screen band is.guided by a suction or couch roll 21 and is looped around a roller 22.The pulp or paper continue to'moveto a dry portion of the machine, ofwhich a part is shown at the right side of Fig. 1. The "pulp or paper 24is carried through the dry portion of the machine by means of a belt 96movingbetween roller pairs 25, 26 and 27, 28. A pressure roller 29 and asuction roller 30, the latter being adapted to lift the pulp or paperfrom the screen band, facethe outside of the screen band. The pressureroller 29 can be lifted upwardly from the screen band by meansof'a'hydraulic or pneumatic piston device 96, 98 and the suction roller30 can be lifted upwardly from-the screen band by means of a hydraulicor penurnatic piston device 97, 99.

The suction'roller 21, the paper lifting roller 30, and the pressurerollers 25 and 27 are connected by means of suction conduits-31 to 35,36 to 38, and 39 to 41 with a blower 43 which is driven by analternating current m'otor42. The conduits 35, 38, and 41 are connectedto different stages of the blower, so that the different desiredsuctionpressures will prevail in these conduits and parts connectedtherewith. A primary water separator 46 is interposed between theconduits 33 and 34, and a secondary water separator 49 is interposedbetween the conduits 34 and 35. A primary water separator 47 isinterposed between the conduits 36 and 37, and a secondary waterseparator 50 is interposed between the conduits 37 and 38. A primarywater separator 48 is interposed between the conduits 39 and 40 and asecondary water separator 51 is interposed between the conduits 40 and41. The water separators take away the water which has been removed fromthe pulp 24. In the diagram Fig. 1, the secondary "separators are shownhigh above the main separators. In the actual plant, the secondary waterseparators are preferably located close to the primary separators. Nosafety head'need be provided in the suction conduits between the mainseparators and the blower, since the latter is provided with anautomatic cutout which will be described later. The water separated inthe main separators 46 to 48 is removed by pumps 52 to 54, respectively.Whenever the water level in a primary water separator reaches apredetermined maximum elevation, a switch 65 interposed in the conduits64 supplying the motor 42 with electric energy is opened by means ofcontrol devices 55 to 57 which will be described later. The controldevices 55, 56, and 57 are individually attached to the primaryseparators 46, 47, and 48, respectively. The control pulse generated inthe device 55 is conducted by means of a conduit 58 to a common conduit61, and therefrom to the switch 65. The control pulse generated in thedevice 56 is conducted to the common conduit'61 by means of a conduit59. The control pulse generated in the device 57 is conducted by meansof a conduit 60- to the common control pulse conduit 61. The devices 55to 57 are also adapted to energize solenoids 69 and to which they areconnected by suitable means 66, 67, and 68, the means 66 being connectedto the common conduit means 61. The solenoids 69 and 70 actuate valves71 and 72, respectively, which valves control the flow of the operatingfluid through conduits 73 and 74, respectively, to the devices 96, 9'8and 97, 99, respectively. Valves 75 and 76 which are suited for manualoperation are arranged in. pipe lines by-passing the valves 71 and 72,respectively. Pressure fluid is supplied through a valve 77, which ismanually operated, to the four valves 71, 72, 75, 76. At normaloperation, i. e. when there is not more water in any of the primaryseparators than is desired, the valves 71 and 72 are held in closedposition by means of the energized solenoids 69 and 70, respectively.The pistons 96 and 97 and the rolls 29 and 30 are inthe illustratedlower position, due to gravity. The roll 29 presses the mat ofpaperagainst the wire screen belt 23, whereas the roll 31 lifts the mat ofpaper from the belt 23 for transferring the mat of paper to the pressportion 'of the machine. If the water level in one of the separators 46to 48 rises above the maximum permissible elevation, the switch 65 whichis actuated by a solenoid 62 is opened and the solenoids 69 and 76 aredeenergized, opening the valves 71 and 72 and supplying a pressurefluid, for example compressed air, into the cylinders 98 and 99 belowthe pistons 96 and 97, respectively, for lifting the pistons andtherolls 29 and 38 connected thereto. The mat of paper which is notdried by the roll 21 and other rolls, which are not shown, after theblower 43 has been stopped by opening the switch 65, can now continue torest on the belt 23, because it is not lifted by the roll 30 and can beguided below the lifted rolls 29 and 30 until it reaches the roller 22,whereupon it drops into a container, not shown. The material may then bebrought into a main reservoir from which it is again returned to theprocess.

Fig.2 illustrates a device which is suitable to form the control devices55 to 57. The device is described in connection with the separator 46.However, it is the same for the separators 47 and 48. The casing 12 ofthe separator 46 is grounded at 13. An electrically insulated horizontalrod 9 extends through an aperture 14-inside of the separator casing 12.The electric insulation 15 of the rod 9 inside of the casing 12 is acidand lye resisting and made, for example, of polyvinylchloride. The rod 9is grounded'through a relais 17 and a source of alternating current 16,so that the rod 9 and the casing 12 form an electric condenser which isinterposed in the auxiliary circuit 18 formed by a spool correspondingto the spool 199 shown in Fig. 4 which will be described later, thesource 16, the ground, and the conduits interconnecting these elements.The spool which forms part of the relais 17 actuates a switch alsoforming part of the relais 17 and being interposed in a main electriccircuit in which also the solenoid 62 actuating the switch 65 and thesolenoids 69 and 70 for operating the valves 71 and 72, respectively,are interposed. A rising water level in the casing 12 changes thegeometric conditions of the condenser and consequently its capacity sothat also the intensity of the alternating current in the circuit 18 ischanged. At a predetermined water level, the spool of the relais -17 issufiiciently energized to open the switch controlling the main electriccircuit so that the solenoid 62 is deenergized and the switch 65 isopened causing stopping of the blower 43, and the solenoids 69 and 70are deenergized causingopening of the valves 71 and 72 and lifting ofthe rolls 29 and 30 from the wire screen belt 23.

In a plant according to Fig. 1 in which the switch 65 maybe actuatedmanually or automatically, i. e. which may not or may include theelements 55 to 61, a mercur tumbler switch illustrated in Fig. 3 may beconnected with'th'e suction conduit 31. The switch 80 includes a. closedglass container 82 adapted'to rock on pivot 81 and containing mercury83, which, in the position shown, connects the contacts 84 and 85. Thelatter are interposed in the circuit formed by the conduits 66 to 68'and the solenoids 69 and 70. The container 82 is connected by a linkage86, 87 with bellows 88, the in terior of which communicates'through aconduit 89 with the conduit 31. When the switch 80 is'in the illustratedposition, the solenoids 69, 70 are energized and the valves 71 and72 areclosed, so that the rolls 29 and 30 are in the illustrated lower oractive position. There is normal operating pressure in the conduit 31and in the bellows 88, so that the paper mat is relatively dry when itpasses under the roller 30. If the pressure in the conduit 31 is toohigh, the bellows is expanded, pushing the rod 87 downward and swingingthe container 82 counterclockwise in Fig. 3 so that the electricconnection between the contacts84, 85 is interrupted. The solenoids 69and 70 are deenergized and the valves 71 and 72 are opened so that thepressure fluid, for example compressedair, moves the pistons 96 and 97upwards.

In anothermodification of the invention, the plant shown in Fig. 1, inwhich the switch 65 may be actuated manually or automatically, i. e.which may not or may include the elements 55 to 61, the solenoids 69 and70 are connected with a source 93 of low tension electric current bymeans of conduits 90 and 91, as shown in Fig. 4. A switch 92 isinterposed in the conduit 90. The switches 92 and 65 are operated by arelais whose coil 94 is interposed in a circuit 198 receiving currentfrom the source 93 and including a switch 197. The latter is actuated bya coil 199 which is interposed in a secondary circuit 18 of atransformer 100. The primary part of the transformer 100 is interposedin the high tension supply lines 64 for the motor 42-. When there is noalternating current in the conduits 64, the coil 199 is deenergized andthe switch 197 is opened, so that the coil 94 is without current and theswitches 65 and 92 are opened. The solenoids 69 and 70 are thereforedeenergized, the valves 71 and 72 are opened and the rolls 29 and 30 arelifted away from the screen belt 23.

While specific embodiments of the invention have been shown anddescribed, it will be apparent to those skilled in the art that variouschanges, modifications, substitutions, additions and omissions may bemade therein without departing from the spirit and scope of theinvention as set forth in the appended claims.

What is claimed is:

1. A paper making machine including an endless screen belt forming aloop and having an upper run supporting the wet mat of paper, a suctionapparatus including at least one blower and a suction device placedadjacent to said screen belt, conduit means interconnecting said deviceand said blower, a roller disposed outside of the loop formed by andbeing normally adjacent to said screen belt, lifting means connectedwith said roller for removing said roller from said screen belt, andactuating means connected with said lifting means for actuating saidlifting means, said actuating means including means responsive to anoperating condition of the machine causing a rise of the pressure insaid suction apparatus beyond a predetermined limit for activating saidactuating means.

2. A paper making machine as defined in claim 1, in which said actuatingmeans include means responsive to the suction pressure in said suctionapparatus for actuating said lifting means upon an excessive pressure insaid suction apparatus.

3. A paper making machine according to claim 2, said lifting meansincluding a cylinder, a piston reciprocatively movable in said cylinderand connected with said roller,

pressure fluid supply means connected with said cylinder for supplying apressure fluid thereinto for moving said piston and said rollerconnected therewith, and a valve in said pressure fluid supply means forcontrolling the supply of pressure fluid to said cylinder.

4. A paper making machine as defined in claim 1, said lifting meansincluding a cylinder, a piston reciprocatively movable therein andconnected with said roller, pressure fluid supply means connected withsaid cylinder for supplying a pressure fluid thereinto for moving saidpiston and said roller connected therewith, a valve interposed in saidsupply means for controlling the supply of pressure fluid to saidcylinder, said actuating means including an electric circuit including asolenoid connected with said valve for actuating said valve, a tumblerswitch interposed in said circuit, and a bellows whose interiorcommunicates with said conduit means, said bellows being connected withsaid tumbler switch for opening the latter upon excessive pressure insaid conduit means and deenergizing said solenoid for actuating saidvalve.

5. A paper making machine as defined in claim 1, in-' cluding anelectric motor for driving said b1ower,electric conduit means forsupplying electric current to said motor, said actuating means includingmeans responsive to the flow of current in said electric conduit meansfor actuating said lifting means upon an interruption of the supply ofelectric current to said motor.

6. A paper making machine according to claim 5, said lifting meansincluding a cylinder, a piston reciprocatively movable in said cylinderand connected with said roller, pressure fluid supply means connectedwith said cylinder for supplying a pressure fluid thereinto for movingsaid piston and said roller connected therewith, and a valve in saidpressure fluid supply means for controlling the supply of pressure fluidto said cylinder, said means responsive to the flow of current in saidelectric conduit means being connected with said valve for operatingsaid valve.

7. A paper making machine as defined in claim 1, including an electricmotor for driving said blower, electric conduit means for supplyingcurrent to said motor, said lifting means including a cylinder, a pistonreciprocatively movable therein and connected with said roller, pressurefluid supply means connected with said cylinder for supplying a pressurefluid thereinto for moving said p1ston and said roller connectedtherewith, a valve interposed in said supply means for controlling thesupply of pressure fluid to said cylinder, said actuating meansincluding an electric circuit including a solenoid connected with saidvalve for actuating said valve, said actuating means including a relaisresponsive to the flow of current in said electric conduit means andbeing associated with said switch for opening said switch upon aninterruption of the supply of electric current to said motor and fordeenergizing said solenoid for actuating said valve.

8. A paper making machine as defined in claim 1, including a waterseparator interposed in said conduit means, said drive means includingan electric motor, electric conduit means for supplying electric currentto said motor, a switch interposed in said electric conduit means, saidactuating means including means responsive to the water level in saidwater separator and being connected with and adapted to actuate saidswitch and said lifting means when the water level in said separatorreaches a predetermined elevation.

9. A paper making machine according to claim 8, said means responsive tothe water level in said water separator including an auxiliary circuitof electric alternating current in which an electric condenser isinterposed, said electric condenser being formed by said waterseparator, the latter including a metallic casing forming one electrodeof the condenser, an electrically insulated rod extending into the saidcasing above the maximum desired water level in the separator andforming the other electrode of the condenser, the water in the separatorforming the dielectric of the condenser, and a relais interposed in saidauxiliary circuit and including a solenoid adapted to be energized upona predetermined electric capacity of the condenser, which capacity isdetermined by the water level in said casing, said actuating meansincluding electrically operated means for actuating said switch and saidlifting means, said relais including 'a switch formingpart of saidelectrically operated means and adapted to be actuated by said solenoid.

10. A paper making machine according to claim 8, said means responsiveto the water level in said water separator including an auxiliarycircuit of electric alternating current in which an electric condenseris interposed, said electric condenser being formed by said waterseparator, the latter including a metallic casing forming one electrodeof the condenser, an electrically insulated rod extending into the saidcasing above the maximum desired water level in the separator andforming the other electrode of the condenser, the water in the separatorforming the dielectric of the condenser, and a relais interposed in saidauxiliary circuit and including a first solenoid adapted to be energizedby a predetermined electric capacity of the condenser, which capacity isdetermined by the water level in said casing, said lifting meansincluding a cylinder, a piston reciprocatively movable in said cylinderand connected with said roller, pressure fluid supply means connectedWith said cylinder for supplying a pressure fluid thereinto for movingsaid piston and said roller connected therewith, a valve interposed insaid supply means for controlling the supply of pressure fluid to saidcylinder, said actuating means including a main electric circuit, asecond solenoid interposed in said main circuit for actuating saidswitch, a third solenoid interposed in said main circuit for actuatingsaid valve, said relais including a switch adapted to be actuated bysaid first solenoid and interposed in said main circuit for controllingenergization of said second and third solenoids.

'11. A paper making machine including an endless screen belt forming aloop and having an upper run supporting the wet mat of paper, a suctiondevice including at least one blower and one suction roll inside of theloop formed by and being adjacent to said screen belt, conduit meansinterconnecting said suction roll and saidblower, a roller disposedoutside of the loop formed by and being normally adjacent to said screenbelt, lifting means connected with said roller for removing said rollerfrom said screen belt, drive means for said blower, means forinterrupting said drive means, and actuating means connected with saidlifting means and with said drive means for coordinating said drivemeans and said lifting means to lift the latter whilst said drive meansare interrupted.

References Cited in the file of this patent UNITED STATES PATENTS2,264,168 Poirer Nov. 25, 1941 2,340,103 Berry Jan. 25, 1944 2,415,351Hornbostel Feb. 4, 1947

